Getting TV show fan art from the JSONRPC API

I can't seem to find out how to get fan art for tv shows over the JSON RPC. Does anyone know how to do this? I can pull the poster banners for the tv series themselves, but fan art I can't seem to figure out

I'm trying to do something similar with movies, how did you get the poster banners? i look at the fanart property of a movie and it gives me a local path, i then try Files.Download and it tells me that it doesn't recognise the Method...